Network management may be conducted at different levels in various types of networks to avoid network failures, and to assure network performance. In a communication network, an element management system (EMS) may be used to supervise and manage network elements within a network. A communication network may also include a network management system (NMS) to manage the overall network by communicating with several EMSs.
In an undersea optical communication system such as a wavelength division multiplexed (WDM) system, for example, terminal or cable stations may be interconnected by cable segments to form a network. The network elements in an optical communication system may include equipment located at a cable station (e.g., terminal equipment and power feed equipment) as well as equipment connected to the cable station (e.g., repeaters and equalizers). In such a system, an EMS may be located at a cable station (or at a separate location) and used to manage the network elements associated with this cable station. The EMS may include one or more servers for performing the element management functions and one or more workstations for providing a user interface (e.g., to display the information associated with the network elements managed by the EMS). An NMS may be located at one of the cable stations or at a separate location for managing the overall optical communication system or network.
The management of a network may include configuration management, fault management and performance management. An EMS may provide fault management by retrieving, storing and/or displaying alarm, event and system messages forwarded by the network elements managed by the EMS. An EMS may provide performance management by retrieving, storing, displaying and/or measuring transmission quality data. A NMS can provide fault management and performance management for the entire network by managing all of the alarm, event and system messages and the transmission quality data forwarded by each EMS. The NMS may display fault and performance information received from each EMS, e.g. on a network topological map.